JP6991725B2 - Photodetector and display device - Google Patents

Description

Embodiments of the present invention relate to a photodetector and a display device.

For example, a video display device including a diffusion control liquid crystal panel and a liquid crystal display panel has been proposed. The diffusion control liquid crystal panel switches between a lens-forming state that diffuses linearly polarized light that vibrates in a predetermined direction and a non-lens-forming state that maintains the directivity of the light and transmits it among the light having directivity in a specific direction. Can be done. In the lens-formed state, a plurality of minute liquid crystal lens portions are formed by applying a voltage to the liquid crystal layer.

Japanese Unexamined Patent Publication No. 2007-264321

An object of the present embodiment is to provide a small and low cost photodetector and display device.

According to this embodiment
A sensor unit including at least one optical sensor, a first substrate, a second substrate, a liquid crystal layer held between the first substrate and the second substrate, and a first facing the optical sensor. Light including a liquid crystal element including a first control electrode and a second control electrode for applying a voltage for forming a lens on the liquid crystal layer, and a sensor unit and a control unit for controlling the liquid crystal element. A detector is provided.

According to this embodiment
A first substrate provided with an optical sensor, a second substrate provided with a light-shielding body having an opening facing the optical sensor, and the optical sensor held between the first substrate and the second substrate. A liquid crystal layer having a first region between the opening and a second region different from the first region, and a first control electrode to which a voltage for forming a first lens is applied to the first region. A display device including a second control electrode and a first display electrode and a second display electrode for applying a voltage to the second region is provided.

FIG. 1 is a block diagram showing a configuration example of the photodetector PDT of the present embodiment. FIG. 2 is a cross-sectional view showing a configuration example of the liquid crystal element LD. FIG. 3 is a plan view showing a configuration example of the liquid crystal element LD. FIG. 4 is a diagram for explaining the first lens 5 formed on the liquid crystal layer 53. FIG. 5 is a diagram for explaining the operation of the first lens 5 shown in FIG. FIG. 6 is a diagram for explaining another shape of the first lens 5 formed on the liquid crystal layer 53. FIG. 7 is a diagram showing a configuration example of the photodetector PDT of the present embodiment. FIG. 8 is a flowchart for explaining a control example of the photodetector PDT. FIG. 9 is a diagram showing an example of a first lens formed on the liquid crystal layer 53. FIG. 10 is a diagram showing another configuration example of the photodetector PDT of the present embodiment. FIG. 11 is a diagram showing another configuration example of the photodetector PDT of the present embodiment. FIG. 12 is a diagram showing another configuration example of the photodetector PDT of the present embodiment. FIG. 13 is a diagram showing another configuration example of the photodetector PDT of the present embodiment. FIG. 14 is a diagram showing a configuration example of a solar system SSYS, which is an application example of the photodetector PDT. FIG. 15 is a flowchart for explaining a control example of the solar system SSYS shown in FIG. FIG. 16 is a diagram showing another configuration example of the photodetector PDT of the present embodiment. FIG. 17 is a diagram for explaining the operation of the liquid crystal element LD and the modulation element MD shown in FIG. FIG. 18 is a cross-sectional view showing a configuration example of the modulation element MD. FIG. 19 is a diagram for explaining a modulation unit MA and a non-modulation unit NMA formed on the modulation element MD. FIG. 20 is a diagram for explaining a control example of the photodetector PDT including the modulation element MD shown in FIGS. 16 and 18. FIG. 21 is a diagram for explaining another control example of the photodetector PDT including the modulation element MD shown in FIGS. 16 and 18. FIG. 22 is a diagram showing another configuration example of the photodetector PDT of the present embodiment. FIG. 23 is a diagram showing a basic configuration and an equivalent circuit of the display device DSP. FIG. 24 is a plan view showing a configuration example of the display device DSP shown in FIG. 23. FIG. 25 is a cross-sectional view showing a configuration example of the display device DSP shown in FIG. 23.

Hereinafter, this embodiment will be described with reference to the drawings. It should be noted that the disclosure is merely an example, and those skilled in the art can easily conceive of appropriate changes while maintaining the gist of the invention, which are naturally included in the scope of the present invention. Further, in order to clarify the explanation, the drawings may schematically represent the width, thickness, shape, etc. of each part as compared with the actual embodiment, but this is merely an example, and the present invention is used. It does not limit the interpretation. Further, in the present specification and each figure, the same reference reference numerals may be given to the components exhibiting the same or similar functions as those described above with respect to the above-mentioned figures, and the overlapping detailed description may be omitted as appropriate. ..

FIG. 1 is a block diagram showing a configuration example of the photodetector PDT of the present embodiment.
The photodetector PDT includes a sensor unit SS, a liquid crystal element LD, and a control unit CT that controls the sensor unit SS and the liquid crystal element LD. Details of the sensor unit SS and the liquid crystal element LD will be described later. The control unit CT includes a timing control unit TCT, a storage unit M, a liquid crystal control unit LCT, and a sensor control unit SCT. The timing control unit TCT controls the liquid crystal control unit LCT and the sensor control unit SCT based on various data stored in the storage unit M and the like. In one example, the storage unit M stores data on a voltage to be applied to the liquid crystal layer in order to form a lens having a predetermined shape on the liquid crystal layer, which will be described later. The liquid crystal control unit LCT controls the liquid crystal element LD, and applies a predetermined voltage to the liquid crystal layer based on the data stored in the storage unit M. The sensor control unit SCT controls the sensor unit SS, drives the optical sensor included in the sensor unit SS, and measures the output from the optical sensor. Further, the sensor control unit SCT outputs the measurement result of the output from the optical sensor to the external device OTD. Further, the sensor control unit SCT outputs the measurement result to the liquid crystal control unit LCT in order to feedback control the liquid crystal element LD. A control example of each part will be described later.

FIG. 2 is a cross-sectional view showing a configuration example of the liquid crystal element LD. The first direction X, the second direction Y, and the third direction Z in the figure are orthogonal to each other, but may intersect at an angle other than 90 degrees.
The liquid crystal element LD includes a first substrate 51, a second substrate 52, a liquid crystal layer 53, a first control electrode E1, and a second control electrode E2. In the illustrated example, the first control electrode E1 is provided on the first substrate 51 and the second control electrode E2 is provided on the second substrate 52, but both the first control electrode E1 and the second control electrode E2 are provided. It may be provided on the same substrate, that is, on the first substrate 51 or the second substrate 52.

The first substrate 51 includes a transparent insulating substrate 511, a first control electrode E1, an alignment film 512, and a feeder line 513. The first control electrode E1 is located between the insulating substrate 511 and the liquid crystal layer 53. The plurality of first control electrodes E1 are arranged at intervals in the first direction X in the effective region 50A. In one example, the width of the first control electrode E1 along the first direction X is equal to or less than the distance along the first direction X of the adjacent first control electrodes E1. The alignment film 512 covers the first control electrode E1 and is in contact with the liquid crystal layer 53. The feeder line 513 is located in the non-effective region 50B outside the effective region 50A.

The second substrate 52 includes a transparent insulating substrate 521, a second control electrode E2, and an alignment film 522. The second control electrode E2 is located between the insulating substrate 521 and the liquid crystal layer 53. The second control electrode E2 is, for example, a single flat plate electrode located on substantially the entire surface of the effective region 50A and extending to the non-effective region 50B. The second control electrode E2 faces the first control electrode E1 via the liquid crystal layer 53 in the effective region 50A. The second control electrode E2 faces the feeder line 513 in the non-effective region 50B. The alignment film 522 covers the second control electrode E2 and is in contact with the liquid crystal layer 53.

The insulating substrates 511 and 521 are, for example, a glass substrate or a resin substrate. The first control electrode E1 and the second control electrode E2 are formed of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). The alignment films 512 and 522 are, for example, horizontal alignment films, and both are aligned along the first direction X.
The first substrate 51 and the second substrate 52 are bonded by the seal 54 in the ineffective region 50B. The seal 54 includes a conductive material 55. The conductive material 55 is interposed between the feeder line 513 and the second control electrode E2, and electrically connects the feeder line 513 and the second control electrode E2.

The liquid crystal layer 53 is held between the first substrate 51 and the second substrate 52. The liquid crystal layer 53 is formed of, for example, a liquid crystal material having a positive dielectric anisotropy. The first control electrode E1 and the second control electrode E2 apply a voltage for forming the first lens 5 to the liquid crystal layer 53.

The liquid crystal control unit LCT controls the voltage applied to the liquid crystal layer 53. The liquid crystal control unit LCT controls the voltage supplied to the first control electrode E1 and the second control electrode E2, respectively, in a mode in which the first lens 5 is formed in the liquid crystal layer 53 and in which a lens is not formed in the liquid crystal layer 53. You can switch between modes. Further, the liquid crystal control unit LCT controls the voltage supplied to each of the first control electrodes E1 to form the first lens 5 at the first position of the liquid crystal layer 53, and the first position of the liquid crystal layer 53. It is possible to switch between the mode in which the first lens 5 is formed at the second position different from the above. Further, the liquid crystal control unit LCT has a mode in which the first lens 5 having the first shape is formed on the liquid crystal layer 53 by controlling the voltage supplied to each of the first control electrodes E1, and the first shape on the liquid crystal layer 53. It is possible to switch between the mode in which the first lens 5 having the second shape different from the above is formed. The illustrated example corresponds to the case where one first lens 5 is formed on the liquid crystal layer 53, but a plurality of first lenses 5 may be formed on the liquid crystal layer 53.

FIG. 3 is a plan view showing a configuration example of the liquid crystal element LD. 3A shows a plan view of the first substrate 51, and FIG. 3B shows a plan view of the second substrate 52.
In the first substrate 51 shown in FIG. 3A, the seal 54 is formed in a frame shape. The plurality of first control electrodes E1 are located inside surrounded by the seal 54 and are arranged at intervals in the first direction X. Each of the first control electrodes E1 is, for example, a strip-shaped electrode extending in the second direction Y. The first control electrode E1 may be a band-shaped electrode extending in the first direction X, or may be an island-shaped electrode arranged in the first direction X and the second direction Y, respectively. The shape of the island-shaped electrode is a polygon such as a quadrangle or a hexagon, or a circle. The feeder line 513 extends in the second direction Y at a position overlapping the seal 54. At least a part of the conductive material 55 included in the seal 54 overlaps the feeder line 513. The wiring board 9 is connected to the first board 51, and electrically connects each of the first control electrode E1 and the feeder line 513 to the liquid crystal control unit LCT.

In the second substrate 52 shown in FIG. 3B, the second control electrode E2 is formed in a rectangular shape and has an end portion E2E extending along the second direction Y. The end E2E overlaps the feeder line 513 and the conductive material 55. That is, the second control electrode E2 is electrically connected to the liquid crystal control unit LCT via the conductive material 55 and the feeder line 513.

FIG. 4 is a diagram for explaining the first lens 5 formed on the liquid crystal layer 53. In FIG. 4, only the configuration necessary for explanation is shown. Here, a case where the same voltage is supplied to the two first control electrodes E11 and E12 and a voltage different from that of the first control electrodes E11 and E12 is supplied to the second control electrode E2 will be described.

In one example, the liquid crystal layer 53 has a positive dielectric anisotropy as described above. The liquid crystal molecule 53M contained in the liquid crystal layer 53 is initially oriented so that its major axis is along the first direction X when an electric field is not formed, and its major axis becomes an electric field when an electric field is formed. Oriented along.

In one example, a voltage of 6 V is supplied to the first control electrodes E11 and E12, and a voltage of 0 V is supplied to the second control electrode E2. Since an electric field is formed along the third direction Z in the region where each of the first control electrodes E11 and E12 and the second control electrode E2 face each other, the major axis of the liquid crystal molecule 53M is in the third direction Z. Orient along. Since an electric field inclined with respect to the third direction Z is formed in the region between the first control electrode E11 and the first control electrode E12, the major axis of the liquid crystal molecule 53M is with respect to the third direction Z. Oriented to incline. In the intermediate region between the first control electrode E11 and the first control electrode E12, almost no electric field is formed, or an electric field is formed along the first direction X, so that the major axis of the liquid crystal molecule 53M is the first. Oriented along the direction X. The liquid crystal molecule 53M has a refractive index anisotropy Δn. Therefore, the liquid crystal layer 53 has a refractive index distribution according to the orientation state of the liquid crystal molecules 53M. Alternatively, the liquid crystal layer 53 has a retardation distribution or a phase distribution represented by Δn · d, where d is the thickness of the liquid crystal layer 53 along the third direction Z. The thickness d is, for example, 10 μm to 100 μm. The first lens 5 shown by the dotted line in the figure is formed by such a refractive index distribution, a retardation distribution, or a phase distribution. The illustrated first lens 5 functions as a convex lens. Further, the illustrated first lens 5 has a shape symmetrical with respect to the normal line N of the liquid crystal element LD.

In the present embodiment, as an example of the liquid crystal element LD provided with the first lens 5, the liquid crystal layer 53 initially oriented substantially horizontally along the main surface of the substrate and the electric field along the direction intersecting the main surface of the substrate are used. The combined method has been described, but it is not limited to this. For example, a liquid crystal layer that is initially oriented substantially perpendicular to the main surface of the substrate may be combined, or may be combined with an electric field along the main surface of the substrate, and the refractive index distribution is variable according to the electric field applied to the liquid crystal layer. A liquid crystal element including the first lens 5 can be realized. The main surface of the substrate here is an XY plane defined by the first direction X and the second direction Y.

FIG. 5 is a diagram for explaining the operation of the first lens 5 shown in FIG.
Here, when the traveling direction of the light is along the third direction Z, the linearly polarized light having the vibration plane along the first direction X is referred to as the first polarization POL1, and the straight line having the vibration plane along the second direction Y. The polarization is referred to as a second polarization POL2. In the illustrated example, the traveling direction of the light is the direction opposite to the arrow indicating the third direction Z. The first polarized POL1 is indicated by an arrow having a horizontal stripe pattern in the figure, and the second polarized POL2 is indicated by an arrow having an oblique stripe pattern in the figure. The light L is, for example, natural light having a random vibration surface, is incident from the outer surface 521A of the insulating substrate 521, and travels from the second substrate 52 toward the first substrate 51.
The first lens 5 has different actions on the first polarized POL1 and the second polarized POL2. That is, the first lens 5 transmits the second polarized POL2 of the natural light L with almost no refraction, and refracts the first polarized POL1. That is, the first lens 5 mainly exerts a focusing action on the first polarized POL1.

FIG. 6 is a diagram for explaining another shape of the first lens 5 formed on the liquid crystal layer 53.
The illustrated first lens 5 is a lens that is asymmetric with respect to the normal N. The first lens 5 has a different refractive index distribution on the left side of the figure, that is, the first region 531 extending over the first control electrodes E11 to E13, and the right side of the figure, that is, the second region 532 extending over the first control electrodes E14 to E16. Have. In such a first lens 5, for example, the respective voltages of the first control electrodes E11 to E17 are set to 6V, 5V, 4V, 3V, 2V, 1V, and 6V, and the voltage of the second control electrode E2 is set to 0V. It can be formed by setting.

FIG. 7 is a diagram showing a configuration example of the photodetector PDT of the present embodiment.
The sensor unit SS includes a substrate 21 and an optical sensor 22 mounted on the substrate 21. In the illustrated example, the sensor unit SS includes one optical sensor 22, but may include a plurality of optical sensors 22. As described above, the liquid crystal element LD includes the first substrate 51, the second substrate 52, and the liquid crystal layer 53, and the details are as described above. Both the first substrate 51 and the second substrate 52 have light transmittance. The light receiving surface 22A of the optical sensor 22 is located directly below the first substrate 51. The light receiving surface 22A may be separated from the first substrate 51 or may be in contact with the first substrate 51. The first lens 5 formed on the liquid crystal layer 53 faces the optical sensor 22. The optical sensor 22 is arranged at a position where the incident light on the liquid crystal element LD is focused by the first lens 5. The optical sensor 22 outputs a signal according to the intensity of the received light. The sensor control unit SCT measures the output from the optical sensor 22.
The example shown in FIG. 7A shows a state in which the light L incident on the liquid crystal element LD is focused by the first lens 5 from a direction substantially parallel to the normal line N. The illustrated first lens 5 is a lens having a shape symmetrical with respect to the normal line N of the liquid crystal element LD. The example shown in FIG. 7B shows a state in which the light L incident on the liquid crystal element LD is focused by the first lens 5 from a direction inclined with an angle θ1 with respect to the normal line N. The illustrated first lens 5 is a lens having an asymmetric shape with respect to the normal N of the liquid crystal element LD. The first lens 5 having these shapes is formed by controlling the liquid crystal element LD by the liquid crystal control unit LCT. The light focused as shown is mainly the first polarized light POL1 as described with reference to FIG.
The control unit CT determines the incident direction of the light L based on the shape of the first lens 5 formed by the control of the liquid crystal control unit LCT and the output from the optical sensor 22 measured by the sensor control unit SCT. be able to. An example of control by such a control unit CT will be described below.

FIG. 8 is a flowchart for explaining a control example of the photodetector PDT. The storage unit M shown in FIG. 1 has a first voltage V1 for forming the first lens 5L of the first shape on the liquid crystal layer 53 in advance, and a first lens 5M having a second shape different from the first shape. The second voltage V2 for forming the first lens 5R having a third shape different from the first shape and the second shape is stored, and the third voltage V3 for forming the first lens 5R is stored.
In the control unit CT, the liquid crystal control unit LCT applies the first voltage V1 read from the storage unit M at a predetermined timing based on the control by the timing control unit TCT to the liquid crystal layer 53 (step ST11). As a result, the first lens 5L having the first shape is formed on the liquid crystal layer 53. In one example, as shown in FIG. 9A, the voltages of the first control electrodes E11 to E17 arranged in the first direction X are set to be smaller in order with respect to the voltage of the second control electrode E2. In this state, an asymmetric first lens 5L extending over the first control electrodes E11 to E17 is formed. At this time, the voltage supplied to the first control electrodes E11 to E17 and the second control electrode E2 corresponds to the first voltage V1 for forming the first lens 5L.
Then, the sensor control unit SCT measures the output from the optical sensor 22 in a state where the first lens 5L is formed (step ST12).

Subsequently, the liquid crystal control unit LCT applies the second voltage V2 read from the storage unit M at a predetermined timing based on the control by the timing control unit TCT to the liquid crystal layer 53 (step ST13). As a result, the first lens 5M having a second shape is formed on the liquid crystal layer 53. In one example, as shown in FIG. 9B, the voltages of the first control electrodes E11 and E17 are mainly set to be the same, and the voltages of the first control electrodes E12 to E16 are 0V or the first. In a state set smaller than the 1 control electrode E11, a symmetrical first lens 5M extending over the first control electrodes E11 to E17 is formed. At this time, the voltage supplied to the first control electrodes E11 to E17 and the second control electrode E2 corresponds to the second voltage V2 for forming the first lens 5M.
Then, the sensor control unit SCT measures the output from the optical sensor 22 in a state where the first lens 5M is formed (step ST14).

Subsequently, the liquid crystal control unit LCT applies the third voltage V3 read from the storage unit M at a predetermined timing based on the control by the timing control unit TCT to the liquid crystal layer 53 (step ST15). As a result, the first lens 5R having a third shape is formed on the liquid crystal layer 53. In one example, as shown in FIG. 9 (c), in a state where the voltage of each of the first control electrodes E11 to E17 is set to be sequentially larger than the voltage of the second control electrode E2, the first An asymmetric first lens 5R is formed over the control electrodes E11 to E17. At this time, the voltage supplied to the first control electrodes E11 to E17 and the second control electrode E2 corresponds to the third voltage V3 for forming the first lens 5R.
Then, the sensor control unit SCT measures the output from the optical sensor 22 in a state where the first lens 5R is formed (step ST16). After that, the sensor control unit SCT compares the outputs measured at each timing, and determines the direction in which the maximum output is obtained as the incident direction of the light (step ST17). For example, when the maximum output is obtained in the state where the first lens 5L of the first shape shown in FIG. 9A is formed, the incident direction of the light is shown in the figure with respect to the normal line N. It can be determined as an inclined direction with an angle θ11 on the left side. Further, when the maximum output is obtained in the state where the first lens 5M of the second shape shown in FIG. 9B is formed, the incident direction of the light is determined as the direction along the normal line N. can do. Further, when the maximum output is obtained with the first lens 5R having the third shape shown in FIG. 9 (c) formed, the incident direction of the light is shown in the figure with respect to the normal line N. It can be determined as an inclined direction with an angle θ12 on the right side.

The first lens 5 having a shape larger than the three shapes shown in FIG. 9 may be formed, and the output from the optical sensor 22 may be measured each time. Further, the shape is continuously changed from the first lens 5L of the first shape shown in FIG. 9 to the first lens 5R of the third shape via the first lens 5M of the second shape, and each time from the optical sensor 22. By measuring the output of, it is possible to measure the incident angle of light.

According to the present embodiment, a liquid crystal element LD capable of forming a first lens 5 having an action of focusing incident light is provided at a position facing the optical sensor 22. Since the first lens 5 is formed by the liquid crystal layer 53, the shape of the first lens 5 can be changed by controlling the orientation state of the liquid crystal molecules. An optical detection device that combines an optical lens formed of glass or resin with an optical sensor requires a moving mechanism that changes the angle or orientation of the optical sensor or the like, but the optical detection device PDT of the present embodiment is the first. Since the shape of 1 lens 5 can be changed, the incident direction of light can be determined without changing the angle or direction of the first lens 5 and the optical sensor 22. Therefore, according to the present embodiment, it is possible to provide a photodetector PDT that is smaller and less costly than a movable photodetector.

Next, another configuration example of the photodetector PDT will be described.

FIG. 10 is a diagram showing another configuration example of the photodetector PDT of the present embodiment. The configuration example shown in FIG. 10 is different from the configuration example shown in FIG. 7 in that the sensor unit SS is provided with a plurality of optical sensors 221 to 225 on the substrate 21. In the illustrated example, the optical sensors 221 to 225 are aligned in the first direction X. The optical sensors 221 to 225 each output a signal according to the intensity of the received light. The number of optical sensors 22 included in the sensor unit SS is not limited to the illustrated example.
The first lens 5 formed on the liquid crystal layer 53 faces the optical sensors 221 to 225. In this configuration example, the shape of the first lens 5 does not change. That is, the voltage applied to the liquid crystal layer 53 is constant, and for example, the first control electrode E1 and the second control electrode E2 are supplied with the second voltage V2 for forming the first lens 5M. ..

The example shown in FIG. 10A shows a state in which the light L incident on the liquid crystal element LD is focused by the first lens 5 from a direction substantially parallel to the normal line N. The light L incident from the normal direction is focused on the optical sensor 223 by the first lens 5. In this case, the output from the optical sensor 223 is the maximum among the plurality of optical sensors. The example shown in FIG. 10B shows a state in which the light L incident on the liquid crystal element LD is focused by the first lens 5 from a direction inclined with an angle θ1 with respect to the normal line N. The light L incident from the oblique direction is focused on the optical sensor 224 by the first lens 5. In this case, the output from the optical sensor 224 is the maximum among the plurality of optical sensors.
As described above, even if the shape of the first lens 5 does not change, the incident direction of the light L can be determined by comparing the outputs from the plurality of optical sensors 22 arranged immediately below the first lens 5. Further, since it is not necessary to change the shape of the first lens 5, the control for forming the first lens 5 can be simplified. It should be noted that the first lens 5 whose shape can be changed as in the configuration example of FIG. 7 may be combined with the configuration example of FIG. 10 including a plurality of optical sensors 22.

The combination of one first lens 5 and the plurality of optical sensors 22 can be variously changed.
In the example shown in FIG. 11, the first lens 5 is a convex lens having a curved surface having a generatrix along the second direction Y and protruding in the third direction Z. The plurality of optical sensors 22 are arranged in the first direction X. In the illustrated first lens 5, the focusing position shifts to the first direction X according to the incident direction of light. Therefore, by comparing the outputs from the optical sensors 22 arranged in the first direction X, it is possible to determine the incident direction of the light L in the XZ plane defined by the first direction X and the third direction Z. can.
In the example shown in FIG. 12, the first lens 5 is a convex lens that is substantially circular in the XY plane defined by the first direction X and the second direction Y and protrudes in the third direction Z. The plurality of optical sensors 22 are arranged in a matrix in the first direction X and the second direction Y. In the illustrated first lens 5, the focusing position shifts in the first direction X and the second direction Y according to the incident direction of the light. Therefore, by comparing the outputs from the optical sensors 22 arranged in a matrix, the incident direction of the light L centered on the third direction Z can be determined.
In the example shown in FIG. 13, the first lens 5X is a convex lens having a curved surface having a generatrix along the first direction X and projecting in the third direction Z. The first lens 5Y is a convex lens having a curved surface having a generatrix along the second direction Y and projecting in the third direction Z. The first lenses 5X and 5Y are arranged in the third direction Z. The plurality of optical sensors 22 are arranged in a matrix in the first direction X and the second direction Y. Also in such an example, the incident direction of the light L centered on the third direction Z can be determined as in the example shown in FIG.

Next, an application example of the photodetector PDT of the present embodiment will be described.

FIG. 14 is a diagram showing a configuration example of a solar system SSYS, which is an application example of the photodetector PDT. The solar system SSYS includes a solar panel SPNL, a photodetector PDT, a support SPB, and a rotation mechanism RTM. The solar panel SPNL uses solar energy to heat, cool, generate electricity, and the like. The configuration of the photodetector PDT is as described above. The support SPB supports the solar panel SPNL and the photodetector PDT. The rotation mechanism RTM rotates the support SPB. The rotation mechanism RTM can be driven not only in the horizontal plane as shown by the arrow A in the figure but also in the elevation angle direction with respect to the horizontal plane as shown by the arrow B in the figure. The photodetector PDT may be built into the solar panel SPNL. It is desirable that the normal line N1 of the photodetector PDT is parallel to the normal line N2 of the solar panel SPNL.

FIG. 15 is a flowchart for explaining a control example of the solar system SSYS shown in FIG.
First, the photodetector PDT determines the incident direction of light according to the configuration example described with reference to FIGS. 7 to 9 or the configuration example described with reference to FIGS. 10 to 13 (step ST21). .. Then, the photodetector PDT determines whether or not the light source, that is, the sun is located in front of the solar panel SPNL, based on the determined incident direction of the light (step ST22). That is, the photodetector PDT determines whether or not the light source is located in front by determining whether or not the incident direction of the determined light is parallel to the normal line N1 of the photodetector PDT. When it is determined that the light source is located in front (that is, the determined incident direction and the normal line N1 are parallel) (step ST22, Yes), the process returns to step ST21 again. On the other hand, when it is determined that the light source is not located in front (that is, the determined incident direction is not parallel to the normal N1) (step ST22, No), the rotation mechanism RTM is driven (step ST23). .. The rotation mechanism RTM rotates the support SPB so that the normal N2 of the solar panel SPNL faces the light source.
By such control, the solar panel SPNL can be directed to the light source following the light source whose position fluctuates, and the utilization efficiency of solar energy can be improved.

Next, another configuration example of the photodetector PDT will be described.

FIG. 16 is a diagram showing another configuration example of the photodetector PDT of the present embodiment. The configuration example shown in FIG. 16 is different from the configuration example shown in FIG. 7 in that it includes a modulation element MD that modulates the incident light. The modulation element MD includes a modulation unit MA that imparts a phase difference to the incident light, and a non-modulation unit NMA that transmits the incident light with almost no modulation. The modulation unit MA, for example, imparts a phase difference of about λ / 2 to the incident light. Here, λ is the wavelength of the incident light. Such a modulation unit MA has a function of rotating the polarization plane by about 90 ° when the incident light is linearly polarized light. The modulation element MD may be composed of a liquid crystal element capable of partially controlling the phase difference, or may be composed of a retardation film having a partially phase difference. The modulation section MA is smaller than the non-modulation section NMA. In one example, the width W1 along the first direction X of the modulation unit MA is smaller than the width W2 along the first direction X of the non-modulation unit NMA. A detailed configuration example of the modulation element MD will be described later, but in the illustrated example, the modulation element MD includes a third substrate 61 and a fourth substrate 62. Both the modulation unit MA and the non-modulation unit NMA are located between the third substrate 61 and the fourth substrate 62. When the modulation element MD is composed of a liquid crystal element described later, the modulation element MD is controlled by the modulation control unit MCT.

In the illustrated example, the sensor unit SS is built in the modulation element MD. That is, the optical sensor 22 is located between the third substrate 61 and the fourth substrate 62. The third substrate 61 corresponds to a substrate on which the optical sensor 22 is mounted. The sensor unit SS is controlled by the sensor control unit SCT.

The liquid crystal element LD includes a third control electrode for forming the second lens 6 on the liquid crystal layer 53 in addition to the first control electrode E1 and the second control electrode E2 for forming the first lens 5 on the liquid crystal layer 53. It includes an E3 and a fourth control electrode E4. Such a liquid crystal element LD is controlled by the liquid crystal control unit LCT.
In one example, the third control electrode E3 is provided on the first substrate 51 in the same manner as the first control electrode E1, and can be formed of the same material as the first control electrode E1. The fourth control electrode E4 is provided on the second substrate 52 like the second control electrode E2, and can be formed of the same material as the second control electrode E2. Further, the second control electrode E2 and the fourth control electrode E4 may be integrally formed. The third control electrode E3 and the fourth control electrode E4 are formed of a transparent conductive material such as ITO or IZO. The third control electrode E3 is a band-shaped electrode extending in the second direction Y, similarly to the first control electrode E1 shown in FIG. The fourth control electrode E4 is a rectangular flat plate electrode similar to the second control electrode E2 shown in FIG. The third control electrode E3 and the fourth control electrode E4 apply a voltage for forming the second lens 6 to the liquid crystal layer 53. The second lens 6 formed on the liquid crystal layer 53 faces the modulation element MD. Of the modulation element MD, the modulation unit MA is arranged at a position where light is focused by the second lens 6. The width W1 of the modulation unit MA is smaller than the width W3 along the first direction X of the second lens 6 (or the distance between the third control electrodes E3 for forming the second lens 6) W3. The solid arrow in the figure indicates the first polarized POL1 having a vibrating surface along the first direction X, and the dotted arrow in the figure indicates the second polarized POL2 having a vibrating surface along the second direction Y. Shows. Further, the shape of the second lens 6 can be freely changed by controlling the voltage supplied to the third control electrode E3 and the fourth control electrode E4, similarly to the first lens 5 described with reference to FIG. Can be changed to.

FIG. 17 is a diagram for explaining the operation of the liquid crystal element LD and the modulation element MD shown in FIG. Of the light incident on the liquid crystal element LD, the first polarized POL1 is focused by the second lens 6 and incident on the modulation element MD, as shown on the left side of the figure. Almost all of the first polarized POL1 is incident on the modulation unit MA and converted into the second polarized POL2. That is, the first polarized POL1 incident on the liquid crystal element LD is converted into the second polarized POL2 and transmitted through the modulation element MD.
On the other hand, of the light incident on the liquid crystal element LD, the second polarized POL2 is incident on the modulation element MD with almost no focusing by the second lens 6, as shown on the right side of the figure. The second polarized POL2 is incident on the modulation section MA and the non-modulation section NMA. As described above, since the non-modulation unit NMA is larger than the modulation unit MA, the light incident on the non-modulation unit NMA among the light incident on the modulation element MD is larger than the light incident on the modulation unit MA. That is, most of the second polarized POL2 incident on the modulation element MD is transmitted in a state where the polarization plane is maintained without being modulated by the unmodulated portion NMA. A part of the second polarized POL2 incident on the modulation element MD is incident on the modulation unit MA and converted into the first polarized POL1. As described above, most of the second polarized POL2 incident on the liquid crystal element LD passes through the modulation element MD as the second polarized POL2.
According to such a configuration example, it is possible to substantially align the polarization directions of the light transmitted through the modulation element MD regardless of the polarization direction of the light incident on the liquid crystal element LD. Light having the same polarization direction is suitable as illumination light for a liquid crystal display device, for example.

FIG. 18 is a cross-sectional view showing a configuration example of the modulation element MD. Here, a case where the modulation element MD is composed of a liquid crystal element will be described. Such a modulation element MD is controlled by the modulation control unit MCT.
The modulation element MD includes a third substrate 61, a fourth substrate 62, a liquid crystal layer 63, a fifth control electrode E5, and a sixth control electrode E6. In the illustrated example, the fifth control electrode E5 is provided on the third substrate 61 and the sixth control electrode E6 is provided on the fourth substrate 62, but the fifth control electrode E5 and the sixth control electrode E6 are both provided. It may be provided on the same substrate, that is, on the third substrate 61 or the fourth substrate 62.

The third substrate 61 includes a transparent insulating substrate 611, a fifth control electrode E5, an alignment film 612, and a feeder line 613. The fifth control electrode E5 is located between the insulating substrate 611 and the liquid crystal layer 63. The plurality of fifth control electrodes E5 are arranged at intervals in the first direction X in the effective region 60A. In one example, the width of the fifth control electrode E5 along the first direction X is larger than the spacing along the first direction X of the adjacent fifth control electrodes E5. The alignment film 612 covers the fifth control electrode E5 and is in contact with the liquid crystal layer 63. The feeder line 613 is located in the non-effective region 60B outside the effective region 60A.

The fourth substrate 62 includes a transparent insulating substrate 621, a sixth control electrode E6, and an alignment film 622. The sixth control electrode E6 is located between the insulating substrate 621 and the liquid crystal layer 63. The sixth control electrode E6 is, for example, a single flat plate electrode located on substantially the entire surface of the effective region 60A and extending to the non-effective region 60B. The sixth control electrode E6 faces the fifth control electrode E5 via the liquid crystal layer 63 in the effective region 60A. The sixth control electrode E6 faces the feeder line 613 in the non-effective region 60B. The alignment film 622 covers the sixth control electrode E6 and is in contact with the liquid crystal layer 63.

The insulating substrates 611 and 621 are, for example, glass substrates or resin substrates. The fifth control electrode E5 and the sixth control electrode E6 are formed of a transparent conductive material such as ITO or IZO. The fifth control electrode E5 is a band-shaped electrode extending in the second direction Y, similarly to the first control electrode E1 shown in FIG. The sixth control electrode E6 is a rectangular flat plate electrode similar to the second control electrode E2 shown in FIG. The alignment films 612 and 622 are, for example, horizontal alignment films. In one example, the alignment film 612 is aligned along the second direction Y and the alignment film 622 is aligned along the first direction X.
The third substrate 61 and the fourth substrate 62 are bonded by the seal 64 in the ineffective region 60B. The seal 64 includes a conductive material 65. The conductive material 65 is interposed between the feeder line 613 and the sixth control electrode E6, and electrically connects the feeder line 613 and the sixth control electrode E6.

The liquid crystal layer 63 is held between the third substrate 61 and the fourth substrate 62. The liquid crystal layer 63 is formed of, for example, a liquid crystal material having a positive dielectric anisotropy. The fifth control electrode E5 and the sixth control electrode E6 apply a voltage to the liquid crystal layer 63 for forming the modulation unit MA and the non-modulation unit NMA shown in FIG.

The modulation control unit MCT controls the voltage applied to the liquid crystal layer 63. The modulation control unit MCT can form the modulation unit MA and the non-modulation unit NMA on the liquid crystal layer 63 by controlling the voltages supplied to the fifth control electrode E5 and the sixth control electrode E6, respectively. Further, the modulation control unit MCT can control the formation positions of the modulation unit MA and the non-modulation unit NMA by controlling the voltage supplied to each of the fifth control electrodes E5. Further, the modulation control unit MCT can freely control the sizes of the modulation unit MA and the non-modulation unit NMA by controlling the voltage supplied to each of the fifth control electrodes E5.

FIG. 19 is a diagram for explaining a modulation unit MA and a non-modulation unit NMA formed on the modulation element MD. In FIG. 19, only the configuration necessary for explanation is shown. Here, a case where a voltage different from that of the sixth control electrode E6 is supplied to the fifth control electrodes E51, E53, and E55 among the plurality of fifth control electrodes E51 to E55 arranged in the first direction X will be described. ..

In one example, the voltage of the fifth control electrode E51, E53, E55 is 6V, and the voltage of the fifth control electrode E52 and E54 and the sixth control electrode E6 is 0V. Further, the liquid crystal layer 63 has a positive dielectric anisotropy as described above. The liquid crystal molecules 63M contained in the liquid crystal layer 63 are twist-oriented by 90 ° in a state where an electric field is not formed. That is, the liquid crystal molecule 63M in the vicinity of the fifth control electrode E51 to E55 is initially oriented so that its major axis is along the second direction Y, and the liquid crystal molecule 63M in the vicinity of the sixth control electrode E6 has its length. The axis is initially oriented along the first direction X. Further, in the state where the electric field is formed, the long axis of the liquid crystal molecule 63M is oriented so as to be along the electric field.

Since an electric field is formed along the third direction Z in the region where each of the fifth control electrodes E51, E53, and E55 and the sixth control electrode E6 face each other, the major axis of the liquid crystal molecule 63M is the third direction. It is vertically oriented along Z. Since no electric field is formed in the region where each of the fifth control electrodes E52 and E54 and the sixth control electrode E6 face each other, the liquid crystal molecule 63M is maintained in the initial alignment state and is twist-oriented.

Here, it is assumed that the first polarized POL1 is incident on the modulation element MD. Of the first polarized POL1 incident from the fourth substrate 62, the first polarized POL1 incident on the region where the fifth control electrode E52 and the sixth control electrode E6 face each other is affected by the twist-oriented liquid crystal molecule 63M. After the polarizing surface rotates and passes through the liquid crystal layer 63, it is converted into a second polarized POL2 having a vibration surface along the second direction Y. Similarly, in the region where the fifth control electrode E54 and the sixth control electrode E6 face each other, the transmitted light is converted into the second polarized POL2. On the other hand, the first polarized POL1 incident on the region where the fifth control electrode E53 and the sixth control electrode E6 face each other is hardly affected by the vertically oriented liquid crystal molecule 63M, the polarization plane is maintained, and the liquid crystal layer is maintained. It passes through 63. Similarly, in the region where the fifth control electrodes E51 and E55 and the sixth control electrode E6 face each other, the transmitted light is the first polarized POL1.
That is, the region where each of the fifth control electrodes E51, E53, and E55 and the sixth control electrode E6 face each other corresponds to the non-modulation section NMA shown in FIG. The region facing the 6-control electrode E6 corresponds to the modulation unit MA shown in FIG.

In the present embodiment, as an example of the modulation element MD, a method in which the liquid crystal layer 63 twist-oriented in the initial alignment state and the electric field along the direction intersecting the main surface of the substrate are combined has been described, but the present invention is limited to this. do not have. Any method can be applied to the above-mentioned modulation element MD as long as it is possible to form a region in which incident light is modulated according to a voltage applied to the liquid crystal layer 63 and a region in which incident light is transmitted without being modulated.

FIG. 20 is a diagram for explaining a control example of the photodetector PDT including the modulation element MD shown in FIGS. 16 and 18.
First, the control unit CT is based on the output from the optical sensor 22 as in the configuration example described with reference to FIGS. 7 to 9 or the configuration example described with reference to FIGS. 10 to 13. The incident direction of the light is determined (step ST31). Then, the control unit CT controls the liquid crystal element LD to form the second lens 6 so as to focus the incident light from the determined incident direction to the modulation unit MA (step ST32). The focusing position of the second lens 6 formed in a specific shape shifts according to the incident direction of light. In the control example described here, the shape of the second lens 6 is changed in order to fix the focusing position regardless of the incident direction of the light. That is, the control unit CT controls the voltage supplied to the third control electrode E3 and the fourth control electrode E4 so that the modulation unit MA forms the second lens 6 having a desired shape as the focusing position.
By such control, even if the position of the modulation unit MA is fixed, it is possible to substantially align the polarization directions of the light transmitted through the modulation element MD regardless of the incident direction of the light.

FIG. 21 is a diagram for explaining another control example of the photodetector PDT including the modulation element MD shown in FIGS. 16 and 18.
First, the control unit CT is based on the output from the optical sensor 22 as in the configuration example described with reference to FIGS. 7 to 9 or the configuration example described with reference to FIGS. 10 to 13. The incident direction of the light is determined (step ST41). Then, the control unit CT controls the modulation element MD to form the modulation unit MA at a position where the second lens 6 focuses the incident light from the determined incident direction (step ST42). In the control example described here, when the shape of the second lens 6 is not changed, the position of the modulation unit MA is changed so as to follow the focusing position that shifts according to the incident direction of the light. That is, the control unit CT controls the voltage supplied to the fifth control electrode E5 and the sixth control electrode E6 so as to form the modulation unit MA at the focused position of the incident light.
By such control, even if the shape of the second lens 6 is fixed, the polarization directions of the light transmitted through the modulation element MD can be substantially aligned regardless of the incident direction of the light.

FIG. 22 is a diagram showing another configuration example of the photodetector PDT of the present embodiment. The configuration example shown in FIG. 22 is different from the configuration example shown in FIG. 16 in that instead of the first lens 5, an opening OP is provided at a position facing the optical sensor 22. The liquid crystal element LD is provided with a light-shielding body BM at a position different from the position where the second lens 6 is formed. An opening OP is formed in the light-shielding body BM. In one example, the opening OP is a pinhole and has a diameter of about 50 to 100 μm. The opening OP may be a slit extending in the second direction Y. The optical sensor 22 is located between the opening OP and the third substrate 61.
Even in such a configuration example, the same effect as the above configuration example can be obtained.

Next, an embodiment of the display device DSP will be described.

FIG. 23 is a diagram showing a basic configuration and an equivalent circuit of the display device DSP.
The display device DSP includes a display area DA for displaying an image and a non-display area NDA surrounding the display area DA. The display area DA includes a plurality of pixels PX. Here, the pixel indicates a minimum unit that can be individually controlled according to a pixel signal, and is present in, for example, a region including a switching element arranged at a position where a scanning line and a signal line, which will be described later, intersect. .. The plurality of pixels PX are arranged in a matrix in the first direction X and the second direction Y. Further, in the display area DA, the display device DSP has a plurality of scanning lines (also referred to as gate lines) G (G1 to Gn) and a plurality of signal lines (also referred to as data wiring or source lines) S (S1 to Sm). , Common electrode CE, etc. are provided. The scanning lines G each extend in the first direction X and are arranged in the second direction Y. The signal lines S each extend in the second direction Y and are lined up in the first direction X. The scanning line G and the signal line S do not necessarily have to extend linearly, and a part of them may be bent. The common electrode CE is arranged over a plurality of pixels PX. The scanning line G is connected to the scanning line driving circuit GD, the signal line S is connected to the signal line driving circuit SD, and the common electrode CE is connected to the common electrode driving circuit CD. The scanning line drive circuit GD, the signal line drive circuit SD, and the common electrode drive circuit CD are controlled by the control unit CT.
Each pixel PX includes a switching element SW, a pixel electrode PE, a common electrode CE, a liquid crystal layer LC, and the like. The switching element SW is composed of, for example, a thin film transistor (TFT), and is electrically connected to the scanning line G and the signal line S. More specifically, the switching element SW includes a gate electrode WG, a source electrode WS, and a drain electrode WD. The gate electrode WG is electrically connected to the scanning line G. In the illustrated example, the electrode electrically connected to the signal line S is referred to as a source electrode WS, and the electrode electrically connected to the pixel electrode PE is referred to as a drain electrode WD. The scanning line G is connected to the switching element SW in each of the pixels PX arranged in the first direction X. The signal line S is connected to the switching element SW in each of the pixels PX arranged in the second direction Y.
The pixel electrode PE is electrically connected to the switching element SW. The common electrode CE faces a plurality of pixel electrodes PE. These pixel electrode PE and common electrode CE function as a first display electrode and a second display electrode that apply a voltage to the liquid crystal layer 13. The pixel electrode PE and the common electrode CE are formed of a transparent conductive material such as ITO or IZO. The holding capacity CS is formed, for example, between the common electrode CE and the pixel electrode PE.
Although the detailed configuration of the display device DSP is omitted here, the display device DSP has TN (Twisted Nematic) mode, PDLC (Polymer Dispersed Liquid Crystal) mode, OCB (Optically Compensated Bend) mode, and ECB ( It has a configuration corresponding to any of various modes such as Electrically Controlled Birefringence) mode, VA (Vertical Aligned) mode, FFS (Fringe Field Switching) mode, and IPS (In-Plane Switching) mode. Further, although the case where each pixel PX is driven by the active method has been described, each pixel PX may be driven by the passive method.
The optical sensor 22 is built in the display device DSP. In the illustrated example, the optical sensor 22 is located in the non-display area NDA. The optical sensor 22 is controlled by the control unit CT.

FIG. 24 is a plan view showing a configuration example of the display device DSP shown in FIG. 23. The display device DSP includes a first substrate SUB1 and a second substrate SUB2. The first substrate SUB1 and the second substrate SUB2 are adhered by a seal SE. The seal SE is located in the non-display area NDA. In the non-display area NDA, the diagonally downward-sloping portion corresponds to the region where the light-shielding body BM is located, and the cross-line portion corresponds to the region where the light-shielding body BM and the seal SE overlap.
When a part of the non-display area NDA is enlarged, the optical sensor 22 overlaps the opening OP formed in the light-shielding body BM. In the example shown in (a) in the figure, the opening OP is a circular pinhole. In the example shown in (b) in the figure, the opening OP is formed in the shape of a slit extending in the second direction Y. In each example, the optical sensor 22 and the opening OP are located on the display area DA side with respect to the seal SE.

FIG. 25 is a cross-sectional view showing a configuration example of the display device DSP shown in FIG. 23.
The first substrate SUB1 includes an insulating substrate 100, an insulating film 110, an alignment film 120, a switching element SW, a pixel electrode PE, an optical sensor 22, a first control electrode E1, and the like. Both the insulating substrate 100 and the insulating film 110 are transparent. In the display area DA, the switching element SW is arranged between the insulating substrate 100 and the insulating film 110. The pixel electrode PE is arranged between the insulating film 110 and the alignment film 120, and is electrically connected to the switching element SW.
In the non-display area NDA, the optical sensor 22 is arranged between the insulating substrate 100 and the insulating film 110. The optical sensor 22 is, for example, a PIN photodiode, and can be formed in the process of forming the switching element SW. The first control electrode E1 is arranged between the insulating film 110 and the alignment film 120. In the illustrated example, the pixel electrode PE and the first control electrode E1 are located in the same layer and can be formed of the same material. In one example, the pixel electrode PE is a reflective electrode and is made of a reflective metal material such as aluminum or silver. The pixel electrode PE may be a transparent electrode formed of ITO or the like.

The second substrate SUB2 includes an insulating substrate 200, an insulating layer 210, a color filter 220, an overcoat layer 230, an alignment film 240, a common electrode CE, a second control electrode E2, a light-shielding body BM, and the like. Both the insulating substrate 200 and the insulating layer 210 are transparent. The insulating layer 210 is arranged over almost the entire display area DA, and is not arranged in the non-display area NDA where the first lens 5 is formed. The insulating layer 210 is a transparent insulating layer and is formed of a transparent organic material. The color filter 220 is arranged between the insulating layer 210 and the overcoat layer 230. The overcoat layer 230 covers the color filter 220. The common electrode CE is arranged between the overcoat layer 230 and the alignment film 240. The common electrode CE is a transparent electrode formed by ITO or the like.
In the non-display area NDA, the shading body BM is arranged between the insulating substrate 200 and the alignment film 240 and has an opening OP. The opening OP is formed at a position facing the optical sensor 22. The second control electrode E2 is arranged between the insulating substrate 200 and the alignment film 240 at the opening OP. The second control electrode E2 can be formed of the same material as the common electrode CE.

The liquid crystal layer LC is held between the first substrate SUB1 and the second substrate SUB2. The liquid crystal layer LC has a first region LC1 between the optical sensor 22 and the opening OP in the non-display area NDA, and a second region LC2 in the display area DA. The first region LC1 has a first thickness D1 between the alignment film 120 and the alignment film 240. The second region LC2 has a second thickness D2 between the alignment film 120 and the alignment film 240. The first thickness D1 is thicker than the second thickness D2. In one example, the second thickness D2 is about 2 to 4 μm, and the first thickness D1 is about 10 to 20 μm. Such a difference between the first thickness D1 and the second thickness D2 is mainly formed by the insulating layer 210. The film thickness D3 of the insulating layer 210 is thinner than the first thickness D1 and thicker than the second thickness D2, and is about 10 μm in one example. In one example, the film thickness D3 is 3 to 4 times the second thickness D2.

As described above, the first control electrode E1 and the second control electrode E2 apply a voltage for forming the first lens 5 to the first region LC1 of the liquid crystal layer LC. As a result, the first lens 5 is formed directly above the optical sensor 22. The first lens 5 focuses the light incident on the second substrate SUB 2 on the optical sensor 22. The optical sensor 22 outputs a signal according to the intensity of the received light.
Further, the pixel electrode PE and the common electrode CE apply a voltage to the second region LC2 of the liquid crystal layer LC. As a result, the retardation of the second region LC2 changes. That is, the orientation state of the liquid crystal molecules contained in the liquid crystal layer LC differs between the off state in which the voltage is not applied to the second region LC2 and the on state in which the voltage is applied to the second region LC2, and the retardation changes. In the reflective display device DSP in which the pixel electrode PE is a reflective electrode and the common electrode CE is a transparent electrode, external light incident through the second substrate SUB2 is transmitted due to the difference in retardation between the on state and the off state. Selectively reflect and display the image.

According to the display device DSP described above, the intensity of the external light incident on the display device DSP can be measured based on the output from the optical sensor 22, and the display brightness of the display device DSP is controlled according to the intensity of the external light. It becomes possible to do. For example, when the intensity of the external light is low, the visibility of the displayed image can be improved by increasing the brightness of the illumination light that illuminates the display device DSP from the side of the second substrate SUB2.
Further, since the incident direction of light can be determined based on the output from the optical sensor 22 as in the above-mentioned photodetector PDT, the display device DSP is directed to a direction in which the observer can easily see the display device DSP. Can be done. For example, when the external light is specularly reflected by the display device DSP, the visibility of the displayed image is improved by controlling the orientation of the display device DSP so that the light source of the external light is not visually recognized by the observer. be able to. As a method for controlling the orientation of the display device DSP, the control example of the solar system SSYS described with reference to FIGS. 14 and 15 can be applied.

As described above, according to the present embodiment, it is possible to provide a small-sized and low-cost photodetector and display device.

It should be noted that the present invention is not limited to the above embodiment itself, and at the stage of its implementation, the components can be modified and embodied within a range that does not deviate from the gist thereof. In addition, various inventions can be formed by an appropriate combination of the plurality of components disclosed in the above-described embodiment. For example, some components may be removed from all the components shown in the embodiments. In addition, components from different embodiments may be combined as appropriate.

PDT ... Optical detection device SS ... Sensor unit 22 ... Optical sensor LD ... Liquid crystal element E1 ... 1st control electrode E2 ... 2nd control electrode E3 ... 3rd control electrode E4 ... 4th control electrode CT ... Control unit M ... Storage unit MD ... Modulator MA ... Modulator NMA ... Non-modulator E5 ... 5th control electrode E6 ... 6th control electrode DSP ... Display device PE ... Pixel electrode (1st display electrode) CE ... Common electrode (2nd display electrode) LC ... Liquid crystal layer LC1 ... 1st region LC2 ... 2nd region 210 ... Transparent insulating layer

Claims (5)

A sensor unit equipped with at least one optical sensor,
The liquid crystal element facing the sensor unit and
The sensor unit, the control unit that controls the liquid crystal element, and
Equipped with
The liquid crystal element is
A first substrate having a plurality of first control electrodes formed in a band shape, and a first substrate.
A second substrate provided with a second control electrode facing the plurality of first control electrodes, and a second substrate.
A liquid crystal layer held between the first substrate and the second substrate is provided.
The first control electrode and the second control electrode are configured to apply a voltage to the liquid crystal layer to form a first lens facing the optical sensor.
The control unit has a first voltage for forming the first lens having a line symmetric shape with respect to the normal line of the liquid crystal element in a cross-sectional view, and an asymmetric shape with respect to the normal line of the liquid crystal element in a cross-sectional view. A storage unit for storing a second voltage for forming the first lens in the liquid crystal layer is provided.
The control unit measures the output from the optical sensor when the first voltage is applied to the liquid crystal layer at the first timing, and the second timing to the liquid crystal layer at the second timing following the first timing. The output from the optical sensor when two voltages are applied are measured, the outputs measured at each timing are compared, and the incident direction of light is based on the shape of the first lens at the timing when the maximum output is obtained. To determine the photodetector. The sensor unit includes a plurality of optical sensors arranged in at least one direction.
The photodetector according to claim 1, wherein the control unit measures outputs from each of the plurality of optical sensors. Further, it is provided with a modulation element having a modulation unit that modulates the incident light.
The liquid crystal element according to claim 1 or 2, further comprising a third control electrode and a fourth control electrode for applying a voltage for forming a second lens facing the modulation element in the liquid crystal layer. Light detector. The photodetector according to claim 3, wherein the control unit controls the liquid crystal element based on the output from the optical sensor to form the second lens that focuses the incident light on the modulation unit. The photodetector according to claim 3, wherein the control unit controls the modulation element based on an output from the optical sensor, and forms a modulation unit at a position where the second lens focuses incident light.

Images